Professor Jordon is well known for his _____ into the habits of the common housefly.

   A. examination    B. introduction

   C. research       D. expression

Professor Jordon is well known for his _____ into the habits of the common housefly.

   A. examination    B. introduction

   C. research       D. expression

Professor Jordon is well known for his _____ into the habits of the common housefly.

Professor Jordon is well known for his _____ into the habits of the common housefly.

1. A.
   examination
2. B.
   introduction
3. C.
   research
4. D.
   expression

 Professor Jordon is well known for his _____ into the habits of the common housefly.

   A. examination    B. introduction

   C. research       D. expression